Trump is shrinking two national monuments cherished by Native Americans — here are the US presidents who protected the most land

A man walks over a natural bridge at Butler Wash in Bears Ears National Monument near Blanding, Utah, U.S., October 27, 2017
REUTERS/Andrew Cullen

President Trump's administration is shrinking Bears Ears National Monument by up to 92%, and Grand Staircase-Escalante National Monument by half.

It will be the largest reduction of a national monument to date.

The Navajo tribe has vowed to fight the decision in court.

President Donald Trump on Monday will announce the reduction of two national monuments in Utah: Bears Ears and Grand Staircase-Escalante.

Trump plans to shrink the amount of protected land in Bears Ears by 77%-92%, in what will be the largest reduction of a national monument to date. His administration plans to cut Grand Staircase-Escalante in half, according to The New York Times. The push was led in part by Secretary of the Interior Ryan Zinke and Utah Senator Orrin Hatch.

Bears Ears was declared a National Monument by former President Barack Obama in 2016. The area is sacred to the local Navajo tribes. Hatch, a longtime opponent of the monument, criticized Obama's decision to protect the area as a "federal land grab."

The monument has been a flashpoint in an ongoing fight between environmentalists who want the land protected, and fossil fuel companies and many rural Westerners, who say the creation of the monuments was a federal overreach and has stifled local economic control.

The Navajo, along with environmental groups and a coalition of local tribes, have vowed to fight Trump's decision in court.

National Monuments are designated by US presidents under the Antiquities Act, which gives them the power to set aside public land for conservation. Former President Theodore Roosevelt signed the act into law in 1906 and used it to protect Muir Woods and the Grand Canyon (which has since become a national park), along with 16 other areas.

While each monument is subject to its own rules, most don't allow any motorized vehicles and forbid using the land for mining or drilling operations.

Obama used the Antiquities Act to protect more than 550 million acres throughout his time in office, significantly more than any of his predecessors.

The chart below shows how many national monuments various US presidents created under the Antiquities Act:

Mike Nudelman/Business Insider

In April, Trump signed an executive order instructing Zinke to review 27 national monuments created since 1996, arguing that previous protections should be reconsidered. Zinke recommended reducing six of the monuments and has pushed for allowing activities like logging and fishing that currently aren't allowed.

Unlike national parks, which are created through Congress, national monuments are designated by US presidents. Trump isn't the first president to shrink a national monument, though the courts haven't ruled on whether presidents actually have the power to shrink monuments. A future legal decision could impact protected lands across the country.

The chart below shows the nine presidents who protected the most land during their time in office. Barack Obama and George W. Bush lead the ranking, though much of the acreage they protected is in the ocean.

Obama created and expanded several massive marine national monuments in the Atlantic and Pacific oceans, and banned drilling for oil and gas in nearly all US waters in the Arctic Ocean.